Biopsychology

• the nervous system is our body's primary internal communication system which is made up of a specialised network of cells.
• The nervous system uses chemicals and electrical signals to communicate.
• The Neuron:

  A) cell body

  B) nodes of ranvier

  C) myelin sheath

  D) axon

  E) dendrites

  F) terminal buttons

  
• The cell body houses the nucleus which contains genetic

  material for the cell.
• Dendrites are branch like structures which carry impulses from neighbouring neurons towards the cell body
• The axon carries impulses away from the cell body and down the cell neuron.
• The myelin sheath protects the axon and speeds up the electrical transmission of the impulse
• The nodes of ranvier are gaps between the myelin sheath which, if continuous, would slow the electrical impulse down. Gaps cause the electrical impulse to jump and therefore speed up the process.
• Terminal buttons are located at the end of dendrites and are used to communicate with neighbouring neurons.
• The cell bodies of motor neurons can be found in the CNS, however their axons would be found in the PNS.
• Sensory neurons are located in clusters - in the PNS - called ganglia.
• Relay neurons make up 97% of all neurons
• Relay neurons are fund mainly in the brain and in visual systems
• Motor neurons connect the CNS to muscles and glands. They are characterised by short dendrites and long axons.

  
• Relay neurons connect motor and sensory neurons to on another as well as connect relay neurons to one another. they are characterised by short dendrites and short axons.

  
• Sensory neurons carry messages from the PNS to the CNS. They have long dendrites and short axons.

  
• Neurons are activated if the charge of a neurotransmitter changes the summation of their overall charge to be positive. This overwhelm of positive charge causes an action potential a.k.a an electrical impulse to be caused and then fired down the axon of the neuron.
• Neurons communicate within groups called neural networks
• Synapses are small gaps which separate neurons.
• neurotransmitters are chemicals which diffuse across the synapse between neurons.
• The presynaptic terminal is the end of the neuron, it is here that synaptic vesicles release neurotransmitters across the synapse following the electrical impulse reaching the terminal.
• Once the neurotransmitters have crossed the synapse - they are absorbed by the post-synaptic receptor in the dendrites of the neighbouring neuron.
• • Axons carry impulses to the synapse
  • Dendrites carry impulses away from the synapse.
• neurotransmitters can categorised into types and each type of neurotransmitter has a specific function.
• Researchers have identified many neurotransmitters in the brain and some in the spinal cord and glands.
• neurotransmitters have a molecular structure which makes them fit into the receptor site perfectly.
• The neurotransmitters which are positively charged have an excitatory effect on the neuron making them more likely to fire. Inhibitory neurons have negative charge and reduce the chance of this happening.
• In a neuron's resting state, it has a positive exterior cell and a negatively charged interior cell.
• The nervous system is made up of the central and peripheral nervous systems.
• The CNS (central nervous system) is made up of the spine and the brain.
• The peripheral nervous system governs unconscious acts and muscle movement as well as receiving information from sensory receptors.
• The cerebral cortex is a 3 mm layer covering the brain and is only present in mammals.
• Minimal species have no brain.
• Only mammals have a cerebral cortex
• Localisation of Function was first put forward by Broca and Wernicke
• Localisation of function is the idea that specific areas of the brain are responsible for specific functions.
• Prior to 'localisation of function' gaining popularity - the holistic view of the brain was widely accepted.
• The holistic view of the brain is the idea that all parts of the brain are involved in all functions of the brain.
• Localisation of function supports the idea that if one area of the brain is damaged then the function(s) associated with it will also be damaged.
• Localisation of function has applicability because it can be used as a basis for neurosurgery. Some mental disorders are treated with neurosurgery based on the premise of localisation of function.